This invention relates to the use of liquid ingredients to provide a pH setting and/or buffering system that is beneficial to the preparation, treating, dyeing, printing and finishing of textile materials such as fiber, yarn, fabric and carpet. The invention also has utility in non-textile industrial operations where processing in water systems occurs, as a replacement and improvement for solid phosphate pH setting and/or buffer ingredients.
For the proper treatment in dyeing and finishing of textile materials, it is the practice to select a pH range that is best suited to the particular operation. These operations can be carried out in water at various temperatures or by application of water suspended or dissolved ingredients directly onto the material. pH is a term used to express a measure of acidity or alkalinity. The pH in these operations can fluctuate widely and if not controlled can cause erratic results. To control pH fluctuations, chemicals are added to the liquid treating bath. Such chemicals used to set or control pH fluctuations are called buffers.
Preparation, treating, dyeing, printing and finishing of textile material such as fiber, yarn, fabric, and carpet involves placing the textile material into a vessel containing water and various compounds dispersed, dissolved, emulsified, or suspended in the water for the purpose of creating the desired effects on the textile material. This water based mixture is called the bath.
The specific process may require a short term immersion in the bath, such as a padding operation in the finishing or preparation area. In this case, the material is run continuously through a trough containing the bath with a dwell time of only a few seconds. The material is then often squeezed dry by means of nip rolls. In other cases, the material is left immersed in the bath for long periods of time (up to 12 hours) to allow chemicals in the bath to act on the textile substrate. Various conditions of temperature, acidity, alkalinity, etc. may be used to produce the desired effects on the material.
Some examples of typical chemicals which may be contained in a textile bath are listed below:
______________________________________ Preparation: surfactants Finishing: resin finish hydrogen peroxide hand builder sodium hydroxide softener silicate lubricant stabilizers pH control pH neutralizers agents (buffers) (buffers) Printing: acrylic polymers thickeners pH control agents (buffers) dyestuffs or pigments surfactants oils softeners Dyeing: surfactant solvent swelling agents pH control agents (buffers) salt softener lubricants Dyestuffs Thickeners Defoamers ______________________________________
Among the commonly used materials for buffering and/or setting pH are Monosodium Phosphate (MSP), Disodium Phosphate (DSP), and Trisodium Phosphate (TSP). These materials are solids, and users have been faced with difficulties in the measuring, handling and dissolving of these materials. For example, these solid products are commonly packaged in 50 or 100 pound bags. These bags must be manually lifted and opened, a procedure that often results in strained muscles, spill waste from broken bags, and poor control over material usage. These powders must then be diluted in a premixing tank before being fed into the textile processing equipment. This is a time consuming operation, and unless the employees involved in the powder dilution are very conscientious, lumps of undissolved product may flow into the equipment or drain lines can clog with solid particles.
These difficulties associated with handling solid phosphates-spillage, lost time from physical strain, disposal or empty bags, time spent in dividing operating difficulties because of incompleted dissolved solids-are of great concern and have been a long-standing problem in dyehouse operations.